mirror of
https://github.com/mozilla/gecko-dev.git
synced 2025-01-31 11:01:40 +00:00
38a6de0fe3
I'm not sure how I tested MOZ_FOR_EACH in bug 1368932, but it turns out it doesn't work with an empty list, despite MOZ_PASTE_PREFIX_AND_ARG_COUNT now supporting 0 arguments. Macros can be tricky, and it ends up being easier to make things work cross-compiler with a separate macro that does the counting, and (re)building MOZ_PASTE_PREFIX_AND_ARG_COUNT on top of that. Then MOZ_FOR_EACH ends up working as expected with an empty list. So this adds a MOZ_ARG_COUNT macro that counts the number of variadic arguments it's given, and derives MOZ_PASTE_PREFIX_AND_ARG_COUNT from it. And this adds a testcase validating that MOZ_FOR_EACH works properly with an empty list as a result. --HG-- extra : rebase_source : 309371d87bd1561fbd2153f44fc1256185045d23
51 lines
1.9 KiB
C++
51 lines
1.9 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#include "mozilla/Assertions.h"
|
|
#include "mozilla/MacroForEach.h"
|
|
|
|
#define HELPER_IDENTITY(x) x
|
|
#define HELPER_IDENTITY_PLUS(x) x +
|
|
static_assert(MOZ_FOR_EACH(HELPER_IDENTITY_PLUS, (), (10)) 0 == 10, "");
|
|
static_assert(MOZ_FOR_EACH(HELPER_IDENTITY_PLUS, (), (1, 1, 1)) 0 == 3, "");
|
|
static_assert(MOZ_FOR_EACH_SEPARATED(HELPER_IDENTITY, (+),
|
|
(), (10)) == 10, "");
|
|
static_assert(MOZ_FOR_EACH_SEPARATED(HELPER_IDENTITY, (+),
|
|
(), (1, 1, 1)) == 3, "");
|
|
|
|
#define HELPER_ONE_PLUS(x) HELPER_IDENTITY_PLUS(1)
|
|
static_assert(MOZ_FOR_EACH(HELPER_ONE_PLUS, (), ()) 0 == 0, "");
|
|
|
|
#define HELPER_DEFINE_VAR(x) const int test1_##x = x;
|
|
MOZ_FOR_EACH(HELPER_DEFINE_VAR, (), (10, 20))
|
|
static_assert(test1_10 == 10 && test1_20 == 20, "");
|
|
|
|
#define HELPER_DEFINE_VAR2(k, x) const int test2_##x = k + x;
|
|
MOZ_FOR_EACH(HELPER_DEFINE_VAR2, (5,), (10, 20))
|
|
static_assert(test2_10 == 15 && test2_20 == 25, "");
|
|
|
|
#define HELPER_DEFINE_PARAM(t, n) t n
|
|
constexpr int
|
|
test(MOZ_FOR_EACH_SEPARATED(HELPER_DEFINE_PARAM, (,), (int,), (a, b, c)))
|
|
{
|
|
return a + b + c;
|
|
}
|
|
static_assert(test(1, 2, 3) == 6, "");
|
|
|
|
int
|
|
main()
|
|
{
|
|
#define HELPER_IDENTITY_COMMA(k1, k2, x) k1, k2, x,
|
|
const int a[] = {
|
|
MOZ_FOR_EACH(HELPER_IDENTITY_COMMA, (1, 2,), (10, 20, 30))
|
|
};
|
|
MOZ_RELEASE_ASSERT(a[0] == 1 && a[1] == 2 && a[2] == 10 &&
|
|
a[3] == 1 && a[4] == 2 && a[5] == 20 &&
|
|
a[6] == 1 && a[7] == 2 && a[8] == 30,
|
|
"MOZ_FOR_EACH args enumerated in incorrect order");
|
|
return 0;
|
|
}
|